The killing of the four hostages is the worst single incident against foreigners in Chechnya since six Red Cross workers lost their lives in December 1996.

Beyond the personal tragedy of the deaths of the four men, this is another heavy blow for President Maskhadov. He has failed to stem the tide of kidnappings that have made his republic a no-go area for foreigners.

He himself compared these murders to the killing of six Red Cross workers in Chechnya in December 1996.

The president repeated the accusation that this was the work of "foreign intelligence services."

That sounds highly implausible, when most of the kidnap gangs in Chechnya are plain criminals, but there is little doubt that the gangs are also trying to undermine Mr Maskhadov's government.

The president's authority has been further weakened this autumn with the murder of one of the commanders of combating kidnapping - Shadid Bargishev - and the political defection of another, Khunkar-Pasha Israpilov.

Hostage-taking continues

There are still at least 100 hostages being held in Chechnya.

The dozen or so foreigners who have been captured and in most cases released have claimed most attention.

One of them, the Frenchman Vincent Cochetel, head of the North Caucasus office of the United Nations High Commissioner for Refugees, is known to be still alive.

But the majority of the 100 or so captives are Chechens and some have been as young as two years old.

Hostage-taking in Chechnya has become a vicious circle. The economy is in ruins and there is no work, which makes it attractive for armed young men to join the many kidnap gangs.

The gangs have become more and more powerful after receiving ransoms of up to $2m for foreign hostages, which they have used to equip themselves even better.

This in turn undermines the government and halts all foreign investment or economic activity.

Projects such as those the four unfortunate engineers were working on, to restore a telephone network, have lapsed.